To assess improvement in live birth rate after progesterone supplementation.

In the absence of properly randomized controlled trials that assessed the efficacy of progesterone in women with RM, a clinical trial with adequate randomization is necessary. In clinical practice, women with RM are frequently seeking advice about the indication for progesterone treatment. Therefore, we have designed a randomized clinical trial to assess the efficacy of progesterone, as compared with placebo, on the live birth rate in women with at least 3 preceding miscarriages.